An evaluation of dermal microcirculatory occlusion under repeated mechanical loads: implication of lymphatic impairment in pressure ulcers

AbstractPressure ulcers are caused by prolonged mechanical loads deforming the underlying soft tissues. However, the mechanical loads for microcirculatory occlusion are unknown. The present study was designed to characterise the simultaneous response of microvascular and lymphatic structures under repeated mechanical loading.The effects of two distinct loading/unloading cycles involving i) incremental pressures 30, 60 and 90mmHg and ii) three repeated cycles of 30mmHg, were evaluated on a cohort of able ‐bodied volunteers. Microvascular response involved the monitoring of transcutaneous gas tensions, while dermal lymphatic activity was estimated from Near Infrared Imaging. Responses were compared during each load and recovery cycle.Changes in microvascular response were dependent on the load magnitudes, with 30mmHg resulting in a reduction in oxygen tension only, while 90mmHg affected both oxygen and carbon dioxide values in most cases (54%). By contrast, lymphatics revealed near total occlusion at 30mmHg. Although there were inter ‐subject differences, temporal trends consistently revealed partial or full impairment under load, with recovery during off‐loading.The pressure required to cause microcirculatory occlusion differed between individuals, with lymphatic impairment occurring at a lower pressure to that of microvascular vessels. This highlights the need for personalised care strategies and regular off ‐loading of vulnerable tissues.
Source: Microcirculation - Category: Research Authors: Tags: ORIGINAL RESEARCH Source Type: research